Field of the Invention
The invention relates to a sensor device for determining ambient conditions of a vehicle, in particular a motor vehicle, comprising at least one transmitter for emitting electromagnetic radiation, in particular infrared radiation, comprising at least three receivers for receiving electromagnetic radiation, in particular infrared radiation, wherein at least two receivers are each assigned to one transmitter for determining precipitation on at least one glass surface, in particular the windscreen of a motor vehicle and wherein at least three receivers are aligned for receiving electromagnetic radiation at different angular regions. The invention further relates to a vehicle having a sensor device according to the invention and a method for determining the position of the sun using a sensor device according to the invention.
Brief Description of the Related Art
Methods and devices for determining ambient conditions are used in many vehicles. The ambient conditions can, for example, comprise weather influences such as the wetting state of the windscreen or the position of the sun. Optical sensor devices, for example can be used to determine the wetting state of the windscreen, in which for example, an infrared signal is coupled into the windscreen and after a defined transit distance of the infrared radiation in the windscreen, it can be determined by means of the coupled-out component of the signal how great is the proportion of total reflections in the windscreen. The proportion of total reflections is here influenced by the wetting of the windscreen, for example, with water. In addition to the wetting state of the windscreen, the position of the sun relative to the vehicle is an important parameter since the position of the sun can be incorporated as a parameter in control programs for air-conditioning systems for example. In many cases, combined rain-light sensors can be used to determine the parameters by using dedicated receivers for the illumination state in addition to the transmitters and receivers for determining rain.
For example DE 10 2009 007 521 B4 describes a method for determining the position of the sun for an air-conditioning system of a motor vehicle. Here solar radiation sensors are used of which one is inclined to the right by a certain angle with respect to the vehicle longitudinal direction and the other is inclined to the left by a certain angle. The angle of the position of the sun with respect to the vehicle longitudinal direction and the intensity of the solar irradiation can be determined by means of the solar radiation sensors. During a rotation of the sensor about a vertical axis, the intensity of the solar irradiation is determined multiple times by the left and the right sensor and the normalized difference is calculated from the intensity values. The elevation of the sun is determined from a stored elevation characteristic of the sensor for the determined normalized difference. For the determined elevation of the sun and the current normalized difference, the azimuth angle is determined from the stored elevation characteristic of the sensor.
A disadvantage of the known devices and methods is that solar position sensors provided especially for this purpose must be used. These additional sensors increase the number of components required and increase the costs of the device.